#include<stdio.h>

unsigned long fact(int n);

int main()
{
	int n;
	unsigned long f;
	scanf("%d",&n);
	f = fact(n);
	
	printf("%d! = %ld\n",n,f);
}

unsigned long fact(int n)
{
	if(n == 1) return 1;
	else return n*fact(n-1);
}
